Sorry for trying to help. If you can't figure this out from page 1 using the cheap set up, then reading 315 pages will not help.
I don't need any help, and I certainly haven't read all 315 pages of this thread, but seeing a seven-year-old thread of this length jump to the top of the forum aroused my curiosity. Your
earlier post was found using the find function of my browser and searching pages 312, 311 and finally 310 for your name (an Advanced Search only returned your five most recent posts).
While it took me longer to read your post then to find it, and it contained sound advice (albeit nothing new), it struck me as a little rich (not to mention self-defeating) that you began by complaining about how lazy people were, but were yourself too lazy to find it and post a link to it (particularly since this should have been much easier for you than any of us, via the My Activity tab or Find latest posts link of your Profile; to date, you've only made eight posts). You clearly put time and effort into making that post, but if you could not be bothered to link to it, how many people, particularly
lazy people, would bother to find it? A minute to search versus a second to click a link: how many people who might benefit from your post do you think would opt for the former?
Lightsabger + max res against diablo = no damage and probably getting healed.
Lightsaber Unique Phase Blade gives you percentage Lightning Absorb, which has a 40% ceiling so it will never result in healing (a net life gain). While its 25% might be useful against Mephisto (for example, after level 20 Conviction reduces Lightning Resist 75% to -50%, 25% LA normally reduces damage equivalent to having LR 25% after LR +75%), it's of no use once you're smiting Diablo because in Hell the missiles fired by his lightning spawn
behind you: you could have LR -100% and you'd still take no damage whatsoever from the lightning because it never hits you once you're in melee range.
It may be counter-intuitive, but because the missiles fired by Diablo's lightning spawn further away from him in Nightmare and Hell, there is a safe zone close to him where you cannot be hit by it. In the image linked below, the safe zone in Nightmare is highlighted in red and that in Hell (which is much larger) is highlighted in orange:
You should be leeching life from lifetap so fast that you won't notice any damage from just the lightning attack (especially when you are surrounded by minions). Here is a hint, your life bulb will be bouncing up and down the whole time. Have fun and enjoy.
Did it occur to you that due to the damage being applied by Venom Lords, diablogeddon and even Diablo himself (which may be overlooked if you judge the length of his lightning based on how long its audible and visible), you might not notice that his lightning is
not actually damaging you as you smite away? All three of his incarnations use the same skill, but the one in the Chaos Sanctuary can be used to eliminate all that clutter and determine the effect of the lightning in isolation: stand next to him in Hell with no integer LA or damage reduction, and life doesn't budge while he's casting lightning.